Double acting tool and die cylinder



July 24, 1962 F. BLATT 3,045,649

DOUBLE ACTING TOOL AND DIECYLINDER Filed Nov. 29., 1960 INVENTOR. LELAND a 8401'? fad- 11 M United States Patent 3,045,649 DOUBLE ACTING TOOL AND DIE CYLINDER Leland F. Blatt, Grosse Pointe Woods, Mich. (22930 Sherwood Ave., Warren, Mich.) Filed Nov. 29, 1960, Ser. No. 72,454 4 Claims. (Cl. 12138) This invention relates to a double acting cylinder, air or hydraulic, and more particularly to a double acting tool and die cylinder.

It is the object of the present invention to provide a double acting cylinder designed for application in conjunction with tools and dies, where it is feasible to have both fluid ports at the rear or blind end of the cylinder.

It is a further object to provide within the tubular piston rod of the cylinder piston, a fixed piston'relatively to which the piston rod is movable together with a guide bushing within one end of the cylinder to slidably receive the said piston rod and wherein the seal for the interior of the said piston rod is protectively retained within the fixedpiston.

It is a further object of the present invention to provide a novel form of double acting cylinder, particularly adapted for tools and dies, adapted for nesting within a bore formed therein and wherein the conduits for delivering pressure fluid are located so' as to direct pressure fluid alternately but to the one end of the cylinder for selective operation upon opposite sides of a movable piston rod, and wherein external piping is eliminated, except for the delivery of pressure fluid and exhausting from the said tool and die. I

It is a further object to provide, as an, attachment for the double acting cylinder, a suitable cylinder bumper of resilient character which is taper locked with the free end of the piston rod for movement therewith.

It is a further object of the present invention to incorporate with the said double acting tool and die cylinder, a disappearing gage pin assembly, adapted for interconnection with the said movable and reciprocal piston rod, together with hardened guide means for the control pin for accurate location thereof and for absorbing side thrust without transmission of shock and wear to the cylinder assembly,

It is a further object ofthe present invention to provide for the said control pin a free floating body within the bore of the. tool to allow for any assembly misalignment between the respective parts. I

These and other objects will be seen from the following specification and claims in conjunction with the appended drawing, in which:

FIG. 1 is a fragmentary longitudinal section of the present double acting tool and die cylinder with the piston in retracted position.

FIG. 2 is a fragmentary partially sectioned view of the resilient cylinder bumper adapted for use with the reciprocal piston rod of said cylinder.

FIG. 3 isan end view thereof.

a FIG. 4 is a fragmentary longitudinal section of the disappearing gage pin assembly adapted for connection with the double acting tool and die cylinder.

It Will be understood that the above drawing illustrates merely a preferred embodiment of the invention and that other embodiments are contemplated within the scope of the claims hereinafter set forth.

Referring to FIG. 1 of the drawings, the present double acting tool and die cylinder is particularly adapted for use in conjunction with a machine tool such as a machine tool and die generally indicated at 11 for projection within the bore 12 of a cylinder assembly 20, there being a counterbore13 formed within a portion of the bed of the tool, the'transverse passages 14 and 3,645,649 Patented July 24, 1962 lCe 15 and the respective conduits 16 and 17 adapted for selectively delivering pressure fluid, either .air or liquid, to opposite ends of the cylinder assembly as hereinafter described and under the control of four-Way valve18, to which is connected conduit P for the delivery of pressure fluid and the additional conduit EX for exhausting fluid from the said cylinder assembly.

The said cylinder assembly 20 includes a head or blind end 21 which is snugly nested within the inner end of bore 12 and which has pressed over its reduced end 22 the elongated cylinder 23. The annular groove 24 in the blind end 21 cooperatively receives set screw 25 within the threaded bore 26 in the said tool 11 for immovably retaining the cylinder assembly 21-23 within the said bore 12.

' Suitable O-ring seals 27 are nested within annular recesses formed in the blind end 21 for cooperation with bore 12, arranged upon opposite sides of fluid passage 14, FIG. 1. v

The stationary tube 19 is axially nested within cylinder 23 and at one end projects into the bore 45 of the cylinder head or blind end 21 and is immovably joined therewith. The opposite end of tube 19 has threaded thereover as at 28 a stationary closed piston 29 with the exterior transverse slot 30for application by a suitable tool such as a screw driver for securing or removal from the tube 19.

A plurality of transverse apertures 31 are formed through wall of tube 19 adjacent the fixed piston 29 to provide communication to the chamber A upon the interior of the movable piston rod 32 which axially surrounds tube 19 in spaced relation.

The inner end of the piston rod 32 is fixedly secured as at 33 within a recessed portion formed in the reciprocal piston 44.

The outer intermediate portion of piston rod 32 slidably projects through the bushing 34 fixedly retained as at 35 Within the outer end of cylinder 23. A suitable closure plug 36 is provisioned and retained upon the interior of the outer end portion of piston rod 32 with a suitable O-ring seal 37 interposed, and defining between the said plug 36 and the stationary piston 29 a cushion chamber38 with access to the atmosphere through the orifice 39 for operation in a manner hereinafter described.

The outer end of piston rod 32 has a tapered portion 40 upon which a bumper assembly may be removably secured, such as shown in FIG. 2, as hereinafter described. Y The seal 41' is nested within an annular groove in the fixed piston 29 for cooperative sealing engagement with the interior wall of the piston rod 32 and is thus protected from wear or damage were it positioned upon the outer diameter of the said piston rod and is also protected from foreign material from the exterior of the cylinder assembly. N

An additional O-ring type of seal 42 is nested within an annular recess within the piston 44 for cooperative engagement with the outersurface of the stationary tube 19.. An additional seal 43 is provisioned within an exterior annular recess in the piston 44 for cooperation with the bore of cylinder 23 completing the seal arrangement Within the cylinder assembly.

,The blind end 21 of the cylinder assembly has formed therein a longitudinal bore 46 which at one end communicates with the bore 14 in the tool 11, and, at its opposite end communicates with the enlarged opening 47 adjacent the reciprocal piston 44. In normal operation of the double acting tool and die cylinderand for one setting of the four-way valve 18, pressure fluid supplied through the conduit P is delivered through conduit 17 intopassage 15, bore 13, passage 45 and upon the interior of the tube 19. Adjacent the outer closed end of said tube the said pressure fluid, either air or liquid, passes through the apertures 31 into the chamber A upon the interior of the piston rod 32, and reacting against the stationary piston 29 operatively engages the reciprocal piston 44 for moving the same to the position shown in FIG. 1, or retaining the same in said position, being the inoperative position thereof.

Should this action have resulted in a movement of the said piston 44 to the position shown in FIG. 1, then in that case any fluid remaining in chamber 47 escapes via passage 46 and the conduit 14 and conduit 16 back to the fourway valve 18 for exhausting through the exhaust conduit indicated at EX.

In order to reverse this operation and to cause a longitudinal control movement of the piston rod 32, the fourway valve 18 has its connections reversed manually or under a remote control so that pressure fluid from the supply P is delivered through conduit 16, passage 14 and passage 46 into chamber 47 in the blind end 21 of the cylinder assembly.

This pressure fluid thus acts upon the piston 44 caus ing it and its connected piston rod 32 to move to the left from the position shown until the said piston 44 operatively engages the stationary bushing 34 at the outer end of cylinder 23. Accordingly with outward movement of piston 44 from the position shown in FIG. 1, the air within chamber B can pass to the atmosphere through the internal bore of the bushing 34 adjacent the piston rod in view of the sliding fit therebetween. At the same time, a fluid which has collected in the chamber A moves through the passages 31 into the tube 19 and at its opposite end through passage 45 and conduit 15 back to the fourway valve 18 and out through the exhaust passage EX.

The relative movement of the piston rod 32 with respect to the fixed piston 29, and in view of the closure 36 defining the cushion chamber 38 thus provides for a cushioned effect upon said movements in view of the fact that said air, as it is compressed on return movement of the piston to the position shown in FIG. 1 can pass outwardly thereof through the orifice 39. Likewise upon outward opening movement of the piston rod 32 to the left of the position shown in FIG. 1, atmospheric air will bleed inwardly through the orifice 39 again cushioning the outward action of the said piston rod.

It is noted also in FIG. 1, a suitable securing O-ring 44' is interposed between the cylinder head 21 or blind end and the internal bore of the cylinder 23. It is contemplated that the orifice 39 would not be necessary if the outer end of piston rod 32 were open. However, in normal operation, there will either be a plug 36 for the cushioning effect above described or provision of some attachment, such as the attachment shown in FIG. 4 hereinafter described.

By applying an orifice of predetermined size relative to the aperture 39, the desired cushioning effect can be obtained in both directions of operation.

The particular configuration of the double acting cylinder is designed for application where it is feasible to have both fluid ports at the rear end of the cylinder or at the blind end thereof. As an accessory to the above described double acting tool and die cylinder, there is shown in FIGS. 2 and 3, a cylinder bumper designed to apply to the cylinder piston rod 32. For this purpose there is provided a lock nut 48 split at 49, and having a slight retaining taper on its ID. at 50 for taper mating with the similar D. 40 on cylinder rod 32, and as shown in FIG. 2 the lock nut 48 is externally threaded at 51 into the supporting body 52 which has mounted thereover the rubber or neoprene cushion 53 to thus provide a rubber bumper or cylinder bumper attachment for the double acting tool and die cylinder above described with respect to FIG. 1.

An additional accessory for the present double acting tool and die cylinder is shown in FIG. 4 in the form of a disappearing gage pin assembly which may be used in conjunction with the same tool 11 also designated in FIG. 4, fragmentarily, terminating at its left end in the work surface 54 with respect to which the gage pin 63 is movable longitudinally thereof.

Within the bore 61 in the said tool 11, which actually forms a continuation of the bore 1'2 shown and described with respect to FIG. 1, there is projected and retained a hardened steel bushing 55, having an exterior annular groove 56 adapted to cooperatively receive the set screw 57 within the bore 58 in the tool 11 for fixedly anchoring the said bushing in position, yet permitting its removal as desired. The said hardened bushing merely has a light press fit within the bore 61 and accordingly is removable as desired on loosening the set screw 57 to which easy access is provided through the bore 58.

The cylindrical body 59 has a loose clearance fit as at 60 within the bore 61 of the tool '11 and is thus free for a limited amount of lateral float relative to the said bore to .allow for any assembly misalignment when the said gage pin assembly is secured to the reciprocal piston rod 32 shown in connection with FIG. 1.

The said body 59 mounts the shank 64 carrying gage pin 63 adjacent its outer end axially thereof, the said shank 64 having a pair of multi-diameter collars for cooperative retaining nesting within the body 59, and retained therein by the retaining ring 66, FIG. 4.

As above described, there is provided the split lock nut 48 similar to that shown in FIGS. 2 and 3 having an internal bore 50 and adapted for a taper fit with the correspondingly tapered outer end 40 of the piston rod 32 by which the said piston rod is interconnected with the gage pin assembly 63-64. The said lock nut 48 is exteriorly threaded as at 62 into the body 59 for completing the assembly.

Accordingly the present double acting tool and die cylinder is effective for operating the reciprocal disappearing gage pin assembly, particularly the gage pin 63 relative to the work surface 54 of the tool for a gaging operation or for a locating operation or for any other decided operation in conjunction with the said tool 11.

While the above described double acting tool and die cylinder has been disclosed as being mounted within the bore 12 or the additional bore 61 in the tool 11, it is contemplated under certain circumstances that it may be desirable to clamp the said cylinder assembly upon the exterior of the tool in any desired manner which will fixedly mount the same thereon.

The above described hardened steel bushing 55 is intended to support the gage pin 63 on the shank 64 thereof and at the same time serve to accurately locate the same with respect to the work surface 54 of the tool. At the same time also, the said bushing 55 is adapted to take any side thrust applied to the gage pin to prevent transmission of shock and wear to the cylinder assembly and thus prolong the life thereof.

Having described my invention, reference should now be had to the following claims.

I claim:

1. In combination with a machine tool having a bed including a work surface and a bore in said bed terminating in said work surface, a double acting cylinder including a bore and a blind end head at one end projected into said bore means on said bed retaining said cylinder Within said bed bore, said head having an axial bore and an additional bore, at their one ends communicating with the cylinder bore and at their other ends respectively connected with fluid supply and exhaust bores in said bed, the outer end of said cylinder being in registry with said work surface, an apertured bushing within the outer end of said cylinder, a reciprocal piston in said cylinder bore, a stationary tube axially joined at one end to said blind end in communication with its axial bore and projecting through said piston, 21 fixedpiston secured upon the outer end of said tube, a tubular piston rod at one end secured to said reciprocal piston arranged concentrically around said tube and in sliding engagement with said fixed piston and with said bushing and extending outwardly of said cylinder, said stationary tube having transverse apertures therein for communication with the chamber in said piston rod, said blind end bores adapted to alternately receive and exhaust respectively pressure fluid for effecting reciprocal movements of said piston rod, a closure for the outer open end of said tubular piston rod adjustably spaced from said fixed piston on movement of said tubular piston rod defining a cushion chamber therebetween, there being an air bleed orifice through the wall of the said tubular piston rod communicating with said cushion chamber.

2. In the double acting tool and die cylinder of claim 1,

, the outer end of said tubular piston rod being tapered, an

interiorly tapered lock nut taper fitted thereon, and a resilient bumper including an internal body threaded over said lock nut. V

3. In combination with a machine tool having a bed including a work surface and a bore in said bed terminating in said Work surface, a double acting cylinder including a bore and a blind end head at one end projected into and retained within said bed bore, said head having an axial bore and an additional bore, at their one ends communicating with the cylinder bore and at their other ends respectively connected with fluid supply and exhaust bores in said bed, the outer end of said cylinder being spaced inwardly of said Work surface, an apertured bushing Within the outer end of saidcylinder, a reciprocal piston in said cylinder bore, a stationary tube axially joined at one end to said blind end in communication with its axial bore and projecting through said piston, a fixed piston secured upon the outer end of said tube, and a tubular piston rod at one end secured to said reciprocal piston arranged concentrically around said tube and in sliding engagement with said fixed piston and with said bushing and extending outwardly of said cylinder, said stationary tube having transverse apertures therein for communication with the chamber in said piston rod, said blind end bores adapted to alternately receive and exhaust respectively pressure fluid for effecting reciprocal movements of said piston rod, a guide bushing secured within the bore of -said bed adjacent and flush with said work surface, a gage pin axially positioned within the bore of said bed for movement through said latter bushing for projection on to said work surface and retraction therefrom, a head on said gage pin, an apertured body retainingly receiving said gage pin head and loosely positioned within the bore of said bed and laterally positionable within said bore, and a lock nut fitted over the outer end of said tubular piston rod and retainingly projected within said body whereby reciprocal movement of said tubular piston rod efiect corresponding reciprocal movements of said gage pin.

4. In combination with a machine tool having a bed including a work surface and a bore in said bed at right angles thereto terminating in said worksurface, a double acting cylinder including a bore and a blind end head at one end projected into and retained within the bore of said bed, said head having an axial bore and an additional bore, at their one ends communicating with the cylinder bore and at their outer ends respectively connected with fluid supply and exhaust bores in said bed, the outer end of said cylinder being spaced inwardly of said work surface, a reciprocal piston within said cylinder, a tubular piston rod connected with said piston and projecting from said cylinder, there being means for hydraulically connecting the interior of said cylinder with said fluid supply and exhaust bores respectively for effecting reciprocal movements of said piston, a hardened guide bushing within the bore of said bed and flush with the said work surface, a disappearing gage pin within the bore of said bed guidably movable through said bushing and projectable onto said work surface and retractable therefrom, an apertured body within the bore of said bed, said gage pin projecting into said 'body, means securing said gage pin within said body, said body being loosely provisioned Within the bore of said bed for lateral floating adjustment therein to correct for misalignment, and a lock nut secured upon the outer end of said tubular piston rod and secured within said body.

References Cited in the file of this patent UNITED STATES PATENTS 1,788,298 Hottel Jan. 6, 1931 2,356,899 Stutter Aug. 29, 1944 2,475,040 Mandl July 5, 1949 

